空氣電磁加熱器影響因素
1.增大空氣加熱器的氣體入口流速,能夠加強空氣電加熱器對流(liu)換熱(re)(re)(re),而(er)降低(di)了空氣加熱(re)(re)(re)器(qi)內電熱(re)(re)(re)元(yuan)件表面溫度(du),不僅有(you)利(li)于(yu)延長空氣加熱(re)(re)(re)器(qi)電熱(re)(re)(re)元(yuan)件的使用壽命,而(er)且使得(de)空氣電加熱(re)(re)(re)器(qi)散熱(re)(re)(re)損(sun)失(shi)減小,因(yin)而(er)空氣換熱(re)(re)(re)器(qi)的效率提高了,但速度(du)如果過大,使得(de)壓力損(sun)失(shi)陡(dou)增(zeng),這將不利(li)于(yu)加熱(re)(re)(re)效率的提高。
2.若其(qi)它條(tiao)件不(bu)變(bian),改變(bian)表(biao)(biao)面負荷(he),空(kong)氣加熱(re)器中電(dian)熱(re)元(yuan)件的(de)壁(bi)溫將(jiang)呈直線變(bian)化,如(ru)果表(biao)(biao)面負荷(he)增(zeng)大,電(dian)熱(re)元(yuan)件的(de)壁(bi)溫將(jiang)增(zeng)大,這將(jiang)降低空(kong)氣加熱(re)器中電(dian)熱(re)元(yuan)件的(de)使用壽命,但是如(ru)果表(biao)(biao)面負荷(he)過(guo)小,壁(bi)溫過(guo)低,空(kong)氣加熱(re)器換熱(re)器的(de)效率又降低了,所(suo)以空(kong)氣加熱(re)器中電(dian)熱(re)元(yuan)件的(de)表(biao)(biao)面負荷(he)的(de)選(xuan)擇比(bi)較重要。
3.空(kong)氣加熱(re)(re)(re)(re)器(qi)中(zhong)(zhong)空(kong)氣終(zhong)溫(wen)T2提高(gao)時(shi)(shi)(shi),由于空(kong)氣粘性(xing)增(zeng)加,氣體雷諾(nuo)數減小,使(shi)得對流換(huan)熱(re)(re)(re)(re)強度(du)降低,空(kong)氣加熱(re)(re)(re)(re)器(qi)中(zhong)(zhong)電熱(re)(re)(re)(re)元(yuan)(yuan)件(jian)(jian)的表面(mian)溫(wen)度(du)同時(shi)(shi)(shi)上升,紅外碳(tan)硫(liu)分析儀使(shi)得散熱(re)(re)(re)(re)損失增(zeng)加,從而降低換(huan)熱(re)(re)(re)(re)器(qi)的效率。當T2提高(gao)過大(da)(da)時(shi)(shi)(shi),電熱(re)(re)(re)(re)元(yuan)(yuan)件(jian)(jian)表面(mian)的溫(wen)度(du)亦會大(da)(da)大(da)(da)升高(gao),致使(shi)一般電熱(re)(re)(re)(re)元(yuan)(yuan)件(jian)(jian)無(wu)法承受,故T2的增(zeng)加通常受到空(kong)氣加熱(re)(re)(re)(re)器(qi)中(zhong)(zhong)電熱(re)(re)(re)(re)元(yuan)(yuan)件(jian)(jian)材料(liao)耐熱(re)(re)(re)(re)性(xing)能的限制。